Heterogeneous bus cross communication method

Abstract

A heterogeneous bus cross communication method belongs to the field of satellite bus communication, and comprises the following steps: judging whether two types of buses are adopted or not according to the data volume and transmission rate of each single machine; setting double buffer areas to perform cross acquisition on the two types of buses, and judging whether data interaction exists between the two types of buses or not; arranging the single machines with data interaction requirements in a crossed manner; polling the A bus single machine, polling the B bus single machine within the response waiting time T, and judging whether data to be exchanged exists in the buffer area A '; data to be exchanged are transmitted while single-machine data of the bus B are collected; and performing cross polling on all single machines on the two types of buses in sequence, and packaging and downloading the data in the buffer area. According to the invention, by adjusting the control strategy of the on-board computer on the two types of buses, the rapid cross acquisition of the cross-bus stand-alone data is realized within the response waiting time, and the information acquisition period is shortened; telemetering acquisition and data uploading tasks are fused, the interaction process between different single machines on two types of buses is simplified, and the uploading data transmission efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite onboard bus communication, and in particular relates to a heterogeneous bus cross-communication method. Background Art

[0002] The satellite's onboard computer usually uses a single communication bus to complete the conventional telemetry collection tasks of each single machine. The communication rate of the bus is fixed, and all single machines are connected to the same bus. When two types of communication buses are introduced, the satellite's onboard computer's polling collection strategy is usually to complete the telemetry collection tasks of each communication bus in turn, and the data exchange work between the two buses will not be interspersed. The data blocks uploaded to certain single machines on the satellite through the measurement and control station on the ground usually complete the entire upload process in the order of transmission from the measurement and control machine, the onboard computer, and the receiving machine. At the same time, the upload process is an independent task and is not integrated with the conventional telemetry collection tasks.

[0003] As satellites become increasingly complex in orbit, the number and technical status of individual machines on board are increasing. Satellites need to introduce and support multiple communication buses, and therefore need to optimize the interaction logic between different communication buses for telemetry acquisition tasks. When multiple communication buses coexist, individual machines on different buses will have the need for frequent data interaction. Currently, there are the following problems with the working conditions of two different communication buses on board:

[0004] (1) In completing the telemetry acquisition task of the entire satellite, if there are two types of heterogeneous communication buses on the satellite, a certain number of single machines will be deployed on each communication bus. The acquisition strategy of the on-board computer is usually to poll and collect all the single machines on a single bus, and then continue to poll and collect the single machines on another bus. After receiving the poll, the single machine has a certain waiting time for response. Usually, there is no operation during the waiting time. The superposition of the waiting time of multiple single machines will cause a waste of computer time on the satellite.

[0005] (2) In the whole-satellite telemetry collection task and the ground data injection task, the on-board computer usually processes the two tasks separately. The injection data needs to be stored in the memory of the measurement and control unit first, and then transferred to the memory of the target receiving unit by the on-board computer. The injection data can be obtained during the whole-satellite telemetry collection task, and the transmission of the injection data is not considered during the telemetry collection task, which brings about a certain degree of delay in the use of the injection data. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a heterogeneous bus cross communication method. The present invention adjusts the telemetry acquisition strategy of the whole satellite when two types of heterogeneous communication buses coexist. During the time when the low-speed bus is waiting for the single machine to respond to the data, the telemetry data of the single machine on the other high-speed bus is cross-collected to improve the computer time utilization rate on the satellite; for the whole satellite telemetry acquisition task and the ground data injection task, for the interactive data existing on different communication buses, i.e., the injection data, the transmission of the injection data of the target receiving single machine is completed while the two types of heterogeneous communication buses cross-execute the whole satellite telemetry acquisition task, thereby avoiding the off-site storage of the injection data and improving the execution efficiency of the injection data.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0008] The present invention provides a heterogeneous bus cross communication method, comprising the following steps:

[0009] Step S1: In combination with the telemetry task of the entire satellite, according to the amount of data generated by each single machine on the satellite and the different transmission rate requirements, determine whether to use two types of heterogeneous communication buses. If so, proceed to step S2; if not, proceed to step S6;

[0010] Step S2: The onboard computer uses two different types of heterogeneous communication buses with different transmission rates. The low transmission rate bus is bus A, corresponding to buffer A'; the high transmission rate bus is bus B, corresponding to buffer B'; according to different technical status and data requirements, each single machine is assigned to a different heterogeneous communication bus, and the onboard computer cross-collects the single machines on bus A and bus B, and at the same time determines whether the single machines on bus A and bus B have data interaction requirements. If yes, it goes to step S3, if not, it goes to step S6;

[0011] Step S3: There is a data exchange requirement between the single machine M on the A bus and the single machine N on the B bus. When cross-collection is performed, the collection order of the single machine M and the single machine N are connected, and after polling the single machine M, the single machine N is polled across the bus.

[0012] Step S4: After polling the single machine M, the onboard computer polls the single machine N within the waiting response time T, and determines whether there is data to be exchanged in the buffer A'. If yes, the computer proceeds to step S5; if no, the computer proceeds to step S6;

[0013] Step S5: sending the data to be exchanged in the buffer A' when receiving the response data from the single machine N, and at the same time putting the response data from the single machine N into the buffer B';

[0014] Step S6: The onboard computer cross-polls all the single machines on the A bus and the B bus in the acquisition order, packs the data in the buffer A' and the buffer B' into the whole satellite downlink telemetry frame, and then transmits it to the ground.

[0015] As a preferred implementation, in step S1, the amount of data generated by each single machine is rapidly varying and slowly varying telemetry data.

[0016] As a preferred implementation, in step S1, determining whether to use two types of heterogeneous communication buses refers to whether two different types of heterogeneous communication buses need to be used simultaneously to complete the onboard platform telemetry collection task.

[0017] As a preferred implementation, the A bus adopts a CAN bus or a 1553B bus.

[0018] As a more preferred implementation manner, the baud rate of the CAN bus is 500 Kbps.

[0019] As a preferred implementation, the B bus uses a high-speed SPI bus or an RS422 bus.

[0020] As a more preferred implementation manner, the transmission rate of the SPI bus is 8 Mbps.

[0021] As a preferred implementation, in step S2, a single machine with a relatively mature technical status, low on-orbit data volume and low transmission rate is allocated to bus A.

[0022] As a preferred implementation, in step S2, a single machine with a relatively new technical status, a high amount of on-orbit data and a high transmission rate is allocated to bus B.

[0023] As a preferred implementation, the waiting response time T ranges from 0.5 ms to 2 ms.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Under the condition that the whole satellite adopts two types of heterogeneous communication buses, the present invention analyzes the data volume and transmission rate of each single machine, reasonably sets the waiting time for the single machine to respond to data, and then adopts a cross-polling strategy for the single machines on the two communication buses to avoid idle and wasted waiting time for responses of multiple single machines, thereby improving the on-board computer time utilization rate and telemetry acquisition efficiency.

[0026] 2. Based on the cross-collection of two types of heterogeneous communication buses, the present invention integrates the design of the whole-satellite telemetry collection task and the ground data injection task, and completes the cross-bus transmission of the injection data to be transmitted in the two tasks in the whole-satellite telemetry collection task, avoiding multiple storage and transfer of the injection data, thereby improving the integration of software tasks and the timeliness of the injection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A typical working mode of cross-bus communication in a heterogeneous bus cross-communication method provided by the present invention.

[0028] Figure 2 A flowchart of a heterogeneous bus cross communication method provided by the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0030] In the present invention, the typical working mode of cross bus communication is as follows Figure 1 The onboard computer exchanges data with an external single machine through a communication interface, and sets independent buffers for the A bus and the B bus. Figure 1 Buffer A' and buffer B' in; the usual polling acquisition strategy is to individually poll and acquire all the single machines on a single bus and then switch to another bus. For example, the onboard computer first polls single machines 1 to 3 on bus A, and then polls single machines 4 to 6 on bus B; after crossing bus A and bus B, bus cross communication is performed, and the onboard computer cross-polls the single machines on bus A and bus B, and completes the transmission of the injected data during the polling process. For example, the onboard computer first polls single machine 1 on bus A, and then polls single machine 4 on bus B, and cross-polls in the order of single machine 1 on bus A, single machine 4 on bus B, single machine 2 on bus A, single machine 5 on bus B, single machine 3 on bus A, and single machine 6 on bus B; finally, after polling all the single machines, they are packaged into a whole-satellite telemetry frame and transmitted to the measurement and control equipment.

[0031] A heterogeneous bus cross-communication method of the present invention sets the number of communication buses and polling collection strategies after analyzing the data volume and transmission rate requirements of each single machine on the satellite, and adopts a cross-communication method for two types of heterogeneous communication buses to complete telemetry data collection and timely transmission of injection data.

[0032] See also Figure 2 To illustrate, a heterogeneous bus cross communication method of the present invention has a specific implementation process as follows:

[0033] Step S1: In combination with the telemetry task of the entire satellite, analyze the amount of fast-changing and slowly-changing telemetry data generated by each single machine on the satellite, and perform whole-satellite machine time analysis according to the bus communication transmission rate commonly used by the satellite platform (generally 500Kbps). According to the amount of data generated by each single machine on the satellite and the different requirements for transmission rate, determine whether it is necessary to add a heterogeneous communication bus during the telemetry data collection process of the satellite platform, that is, whether it is necessary to use two different types of heterogeneous communication buses at the same time to complete the telemetry collection task of the satellite platform. If so, proceed to step S2; if not, proceed to step S6.

[0034] Step S2: setting a double buffer to perform cross-collection on the two types of buses, and determining whether there is a need for data exchange between the two types of buses;

[0035] The onboard computer uses two different types of heterogeneous communication buses with different transmission rates to complete the telemetry acquisition task of the onboard platform. Among them, the low transmission rate bus is the A bus, which uses commonly used buses on the satellite, such as CAN bus, 1553B bus, etc.; the high transmission rate bus is the B bus, which uses high-speed SPI bus, RS422 bus, etc., and the transmission rate of the SPI bus is 8Mbps; these two different types of heterogeneous communication buses with different transmission rates correspond to two different receiving buffers, A bus corresponds to buffer A', and B bus corresponds to buffer B'.

[0036] According to different technical status and data requirements, each single machine is assigned to different heterogeneous communication buses; among them, single machines with relatively mature technical status, low on-orbit data volume and transmission rate are assigned to bus A; single machines with relatively new technical status, high on-orbit data volume and transmission rate are assigned to bus B. In order to improve the overall acquisition rate under the heterogeneous communication bus, the on-board computer cross-collects the single machines on bus A and bus B; at the same time, it determines whether the single machines on bus A and bus B have data interaction requirements. If yes, it goes to step S3, if not, it goes to step S6.

[0037] Specifically, the A bus can use a CAN bus with a baud rate of 500Kbps; the B bus can use an SPI bus with a transmission rate of 8Mbps. According to different technical status and data requirements, each single machine is divided into the CAN bus and the SPI bus respectively; the single machines with relatively mature technical status such as power supply, attitude control, measurement and control, and intersatellite, and low telemetry data volume and transmission rate requirements are allocated to the conventional CAN bus; the single machines with relatively new technical status such as real-time processing single machine and AI single machine, and high telemetry data volume and transmission rate requirements are allocated to the SPI bus. In order to improve the overall acquisition rate under the coexistence of the CAN bus and the SPI bus, the single machines on the CAN bus and the SPI bus are cross-collected, that is, the CAN bus power single machine is collected, the SPI bus real-time processing single machine is collected, and then the CAN bus attitude control single machine is collected; at the same time, it is judged whether the single machines on the CAN bus and the SPI bus have data interaction requirements. If yes, step S3 is entered, and if not, step S6 is entered.

[0038] Step S3: cross-arrange the single machines that have data interaction requirements;

[0039] There is a need for data interaction between the single machine M on the A bus and the single machine N on the B bus. When the onboard computer performs cross-collection on the single machines on the A bus and the B bus, the collection sequence of the single machine M and the single machine N is connected, that is, after polling the single machine M, the single machine N is polled across the bus.

[0040] Specifically, bus A can adopt a CAN bus with a baud rate of 500Kbps, and bus B can adopt an SPI bus with a transmission rate of 8Mbps; single machine M is an intersatellite single machine, and single machine N is a real-time processing single machine; the intersatellite single machine on the CAN bus can receive uploaded data from the ground, and the real-time processing single machine on the SPI bus has the need for software replacement in orbit, and needs to receive uploaded data frequently, that is, there is a need for data exchange between the real-time processing single machine on the SPI bus and the intersatellite single machine on the CAN bus; therefore, when the onboard computer cross-collects the single machines on the CAN bus and the SPI bus, the collection sequence of the intersatellite single machine and the real-time processing single machine is connected, that is, after polling the intersatellite single machine, the real-time processing single machine is polled across the bus.

[0041] Step S4: poll the A bus single machine, poll the B bus single machine within the waiting response time T, and determine whether there is data to be exchanged in the buffer A';

[0042] After polling the single machine M on the A bus, the onboard computer polls the single machine N on the B bus within the waiting response time T, and determines whether there is data to be exchanged in the buffer A'. If yes, it goes to step S5, if not, it goes to step S6.

[0043] Specifically, the A bus can be a CAN bus with a baud rate of 500Kbps, and the B bus can be an SPI bus with a transmission rate of 8Mbps; the single machine M is an intersatellite single machine, and the single machine N is a real-time processing single machine; when the on-board computer polls the intersatellite single machine on the CAN bus, it can collect the telemetry data of the intersatellite single machine and the ground injection data received by it. After polling the intersatellite single machine, the real-time processing single machine on the SPI bus is polled within the waiting response time T (0.5ms~2ms) (each cross-communication between single machines on the SPI bus can save a waiting response time T), and it is determined whether there is data to be exchanged (the above injection data) received by the intersatellite single machine in the buffer A'. If yes, it goes to step S5, and if not, it goes to step S6.

[0044] Step S5: while collecting the single machine data of bus B, transmit the data to be exchanged;

[0045] The latest data to be exchanged in the buffer A' corresponding to the A bus is sent out when receiving the response data of the single machine N on the B bus, and the response data of the single machine N is put into the buffer B' corresponding to the B bus.

[0046] Specifically, bus A can adopt CAN bus with a baud rate of 500Kbps, and bus B can adopt SPI bus with a transmission rate of 8Mbps; single machine M is an intersatellite single machine, and single machine N is a real-time processing single machine; when the shortest waiting response time T (T=0.5ms), according to the 8Mbps transmission rate of the SPI bus, the amount of data that can be transmitted within 0.5ms is 500B, which can cover the telemetry package of the real-time processing single machine on the SPI bus and the data injected once on the ground; the SPI bus works in a simultaneous data transmission and reception mode, so when the onboard computer receives the response data (within 500B) of the real-time processing single machine on the SPI bus, it can synchronously send the latest data to be exchanged (within 500B) in the buffer A' corresponding to the CAN bus to the real-time processing single machine, and then put the response data of the real-time processing single machine into the buffer B' corresponding to the SPI bus.

[0047] Step S6: The onboard computer cross-polls all the single machines on the A bus and the B bus according to the predetermined acquisition sequence, packs the data in the buffer A' and the buffer B' into the whole satellite downlink telemetry frame, and then transmits it to the ground.

[0048] The present invention provides a heterogeneous bus cross-communication method. Aiming at the working condition that the satellite onboard platform adopts two types of heterogeneous communication buses to complete the telemetry task of the whole satellite, firstly, the corresponding relationship between each lower computer and the communication bus is adjusted according to the different functional requirements of each lower computer, that is, the single machine; then, by adjusting the control strategy of the onboard host to the two types of heterogeneous communication buses, the cross-bus lower computer data is quickly cross-collected within the waiting response time, the information collection cycle is shortened, and the telemetry collection task can be integrated with the data injection task, so as to simplify the interaction process between different lower computers on the two types of heterogeneous communication buses, improve the transmission efficiency of the injection data, and benefit the improvement of the overall performance of the satellite.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heterogeneous bus cross communication method, characterized in that: The following steps are involved: Step S1: In combination with the telemetry task of the entire satellite, according to the amount of data generated by each single machine on the satellite and the different transmission rate requirements, determine whether to use two types of heterogeneous communication buses. If so, proceed to step S2; if not, proceed to step S6; Step S2: The onboard computer uses two different types of heterogeneous communication buses with different transmission rates. The low transmission rate bus is bus A, corresponding to buffer A'; the high transmission rate bus is bus B, corresponding to buffer B'; according to different technical status and data requirements, each single machine is assigned to a different heterogeneous communication bus, and the onboard computer cross-collects the single machines on bus A and bus B, and at the same time determines whether the single machines on bus A and bus B have data interaction requirements. If yes, it goes to step S3, if not, it goes to step S6; Step S3: There is a data exchange requirement between the single machine M on the A bus and the single machine N on the B bus. When cross-collection is performed, the collection order of the single machine M and the single machine N are connected, and after polling the single machine M, the single machine N is polled across the bus. Step S4: After polling the single machine M, the onboard computer polls the single machine N within the waiting response time T, and determines whether there is data to be exchanged in the buffer A'. If yes, the computer proceeds to step S5; if no, the computer proceeds to step S6; Step S5: sending the data to be exchanged in the buffer A' when receiving the response data from the single machine N, and at the same time putting the response data from the single machine N into the buffer B'; Step S6: The onboard computer cross-polls all the single machines on the A bus and the B bus in the acquisition order, packs the data in the buffer A' and the buffer B' into the whole satellite downlink telemetry frame, and then transmits it to the ground.

2. A heterogeneous bus cross communication method according to claim 1, characterized in that: In step S1, the amount of data generated by each single machine is the amount of rapidly varying and slowly varying telemetry data.

3. A heterogeneous bus cross communication method according to claim 1, characterized in that: In step S1, judging whether to use two types of heterogeneous communication buses refers to whether it is necessary to use two different types of heterogeneous communication buses at the same time to complete the telemetry collection task of the onboard platform.

4. A heterogeneous bus cross communication method according to claim 1, characterized in that: The A bus adopts CAN bus or 1553B bus.

5. A heterogeneous bus cross communication method according to claim 4, characterized in that: The baud rate of the CAN bus is 500 Kbps.

6. A heterogeneous bus cross communication method according to claim 1, characterized in that: The B bus adopts a high-speed SPI bus or an RS422 bus.

7. A heterogeneous bus cross communication method according to claim 6, characterized in that: The transmission rate of the SPI bus is 8 Mbps.

8. A heterogeneous bus cross communication method according to claim 1, characterized in that: In step S2, single machines with relatively mature technical status, low on-orbit data volume and transmission rate are allocated to bus A.

9. A heterogeneous bus cross communication method according to claim 1, characterized in that: In step S2, a single machine with a relatively new technical status, a high amount of on-orbit data and a high transmission rate is allocated to the B bus.

10. A heterogeneous bus cross communication method according to claim 1, characterized in that: The waiting response time T ranges from 0.5 ms to 2 ms.

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